1. Field of the Invention
The present invention relates to a socket for an electrical part for detachably accommodating and holding an electrical parts such as a semiconductor device (what is called an “IC package” hereinafter) and more precisely to a socket for an electrical part capable of preventing a mold guide for guiding the electrical part from being damaged.
2. Prior Art of the Invention
As a conventional “socket for an electrical part” of this kind, there has been provided an IC socket for detachably accommodating and holding an IC package as an “electrical part” (refer to FIG. 13).
This IC package 6 is generally called as a “gullwing type” having a rectangular-shaped package body 6b, from two sides opposite to each other of which a plurality of IC leads 6a as “terminals” project laterally to form into a crank shape.
The IC socket, on the other hand, includes a socket body 1 in which an accommodation portion 1a for accommodating the IC package 6 is provided, and a plurality of contact pins 2 contacting the IC lead 6a of the IC package 6. This contact pin 2 has a movable contact piece 3 having a movable-side contact portion 3a contacting with or separating from an upper surface of the IC lead 6a. On the socket body 1, a mold guide 1b for guiding a periphery of the IC package 6 and supporting a lower surface of the IC lead 6a is formed. In addition, the socket body 1 is further provided with a vertically movable operation member 4. By moving the operation member 4 downward against the urging force etc. of a movable contact piece 3 of the contact pin 2, an operation piece 3b of a movable contact piece 3 of the contact pin 2 is pushed outward by a cam portion 4a of the operation member 4.
Thus a spring portion 3c of the movable contact piece 3 of the contact pin 2 is elastically deformed so that the movable-side contact portion 3a is moved away from the IC lead 6a. On the contrary, when the operation member 4 moves upward, the movable-side contact portion 3a returns back by the elastic force of the spring portion 3c and contacts to the upper surface of the IC lead 6a. And hence the IC lead 6a is clamped by both the movable-side contact portion 3a and the mold guide 1b, thus establishing an electrical connection between the contact pin 2 and the IC lead 6a. 
Under a situation that the IC package 6 is not accommodated in the socket body 1 (non-accommodation state), the movable-side contact portion 3a abuts on the mold guide 1b. This mold guide 1b is configured to be relatively narrow so that the mold guide can be inserted into a space (h) between a vertical portion of the crank shaped IC lead 6a and the package body 6b. 
A socket of such kind is disclosed, for example, in Patent Document 1 (Japanese unexamined Patent Publication No. H11-26127 A1)
However, in the conventional structure of the socket mentioned above, under a situation that the IC package 6 is not accommodated, an end edge portion of the movable-side contact portion 3a is structured to be landed on the mold guide 1b of the socket body 1. Accordingly, the movable-side contact portion 3a made of metal abuts on the mold guide 1b made of synthetic resin, therefore there is a fear that the mold guide 1b could be damaged.
In addition, when the end edge portion of the movable-side contact portion 3a is somewhat displaced or slid, the end edge portion of the movable-side contact portion 3a is liable to drop off from the end edge portion of the narrow mold guide 1b. When the dropping off occurs, the contact pin 2 itself is likely to be damaged.